This invention relates in general to measuring, and more particularly to an apparatus for measuring the space between locations on surfaces without actually contacting those surfaces.
In certain medical procedures it is desirable to know the width of a body canal or passage or to know the size of an obstruction within the same. For example, when placing an endotracheal tube, the physician should have a reasonable idea as to the size of the trachea so as to be able to select a tube of appropriate diameter. Similarly, premature infants sometimes experience difficulty breathing, and in such situations it is helpful to know the size of the infant's trachea.
An instrument known as a bronchoscope exists for observing the surface that lines the trachea, and this device not only possesses the optics for making the observation, but also transmits light to and projects it onto the surface to provide enough illumination for a meaningful observation. Even so, a bronchoscope does not have the capacity to measure the width or diameter of the passage which is observed through it.
Other devices or scopes exist for illuminating and observing the walls of other body canals, and these scopes likewise do not provide any means for measuring the width of the canal so observed or lesions on the linings of body cavities. Irrespective of the type of scope, it is usually not inserted directly into the canal, but instead through a sheath which is first placed in the canal.
The present invention provides a bronchoscope or similar scope with the capacity to measure the width of a body canal or obstruction in it in addition to observing the canal, and the measurement is made without actually contacting the surfaces from which the measurements are taken. Not only is the device suitable for use by the medical profession, but with slight adaptations, it finds utility in other fields as well, indeed in practically any circumstance where a measurement must be taken from the interior of a tube or cavity. In essence, the apparatus is an optical caliper.